Plimogz

I had just put on a new pair of Schwalbe Big Apples, expecting to ride them for many thousands of miles before their abundant rubber wore away, as the previous set had done. On their second or third day out, I hit some particularly nasty metal road debris which left a bad gash through the thickest part of the thread, through the puncture protection and ripped 1/4" to 3/8" worth of cords.

I find that I cannot bring myself to toss the otherwise new, albeit compromised, tire; so today I finally mounted it in the back with a Mr. Tuffy liner in an attempt to keep stuff from getting at the tube, and to keep the tube from herniating through the tire.

Now I am looking for predictions as to what will be the outcome of this: Does anybody think that this end up with something poking through the liner? Or will the damaged tire continue ripping along the already severed cords? Or might it be something I have not thought of...

Or is anyone optimistic about my chances of racking up some miles on this unlucky tire?

Andrew R Stewart 

If the Tuffy covers the cut well enough then all should be right, for a cut tire... Andy

eastbay71

Mine worked great until it didn't. And then I was walking.... a very long walk.

Plimogz

Although I usually only pack several patches and a couple of tubes of vulcanizing fluid (one unopened -- I will not be making that mistake again), today I packed a folding-bead tire and a spare tube.

FBinNY 

It's impossible to predict without seeing the extent of the damage, and (IMO) the location and orientation of the cut.

The primary stress on the tire body is hoop stress, so a lengthwise cut tends to open faster than one running across the trea. But even that's not assured because the tire plies run on the bias at 45° to the line of the tire. Like you, I don't like to toss cut tires that are otherwise in great shape. My fix is to make a boot, preferably from heavy woven polyester fabric, and apply it to the area so the boot and tire plies line up. I make these pretty large so there's plenty of bonding surface, and I wind one side under and around the bead, so the rim helps hold it in place.

Just keep an eye o it, and it may last days, weeks or outlast the rest of the tire.

CliffordK

I've got a Schwalbe Marathon that needs to be repaired and remounted. My theories is that the really thick rubber tires just pick up bigger chunks of glass, and thus show worse damage. It's puncture was in the first week or so.

My first attempt at a tire boot was to use one of the Park boots. 500 miles or so, and the natural flex of the tire around the boot chewed through my tube. So, I taped up the boot with electrical tape... and another 500 miles or so and it literally shredded the boot. Plus, a hole wore through the center of the boot and almost through the tube (I was lucky).

The tire was taken off for the summer, and hasn't been remounted.

On another thinner tire I tried another Park boot and the road chewed through it in a couple hundred miles.

I now have one tire that had a sidewall puncture and damage. I put patches to the outside of the sidewall where it was damaged, and the one puncture that went through I've backed up with a radial tire patch on the inside. The radial tire patch is a bit stiff, but so far, so good, but it is still early with that experiment.

Anyway... it depends on how good your tire liner is. It could last forever, or debris may eventually cut through it (or increase the size of the hole).

miamijim

Its toast and you know its toast. If you looking for someone to justify your frugality...its not me.

Plimogz

It is partly frugality, yes, but it is also curiosity. I have not had opportunity to mess with something like this before; whatever happens I will likely learn something new.

Maybe after this I will resign myself that a tire similarly damaged is only good for the trash. Maybe the tire liner will do better than I had hoped. Maybe I will investigate improving my tire booting competence in a manner along what FBinNY has suggested.

jyl

If you need to carry a spare tire when riding the booted tire, then you really haven't gained anything by riding the booted tire, IMO.

fietsbob

best tire always goes on front.

sch

If you are riding at 25-30# psi and have a large thick boot inside the tire well glued as per FB-NY I would ride the tire
assuming the tear is not obviously bulging. You could try filling the cut tread with Goop or such. Not sure I would go on long
radius rides until I saw how the tire was handling it but very low psi tires like yours should do well booted compared with
100 psi 23 mm thin tread bike tires.

CliffordK

A large thick boot at low pressure will bump, and becomes annoying.

At higher pressures, there is less of a bump feeling.

Miele Man

If/when that tire were to fail how far would you have to walk or how long would you have to wait for a lift?

Tires are one of the things i want to be positive aren't going to leave me stranded especially when it's really hot and humid and there's little shade. IMHO, tire boots are a temporary fix to get you home or until you can replace the tire. Many people do ride a botted tire foe quite a long way but i prefer knowing my tires are good.

If that boot/tire fails it could cause a blowout of the tube that also can't be fixed.

I'd get a new tire and scrap that one.

Cheers

ThermionicScott 

That's my thinking, too.

andr0id

I feel your pain, but I'm going to agree with Jim. A tire with a cut in cords allows two things to happen. Grit and other debris work their way in through the cut and cut through the boot and then the tube OR the cut nips and abrades the tube and puts a hole in it.

It sucks to toss a pretty new tire, but it's the right thing to do to maintain your sanity.

I just write it off now as a cost of riding. Most of the time, I get good mileage out of a tire, sometimes I don't.

FBinNY 

As someone who had to develop decent booting skills because of bad tire luck on extended tours, I disagree with the naysayers.

Tires can be booted, and while this is usually considered a last ditch method to get rolling when it's the only option, I can attest to how long a properly repaired tire can last. IME boot failure (tire failure at the repair) is rarely the cause of the next flat or what kills the tire off. In other words, a properly booted tire is comparable to a properly patched tube.

The key here is to do a proper repair, and of course depends on the extent of the damage, but I've repaired gashes over 1/2" long, and in one desperate case, a rim line gash over an inch long (brake shoe wear), though the rim line repair was more involved, and we replaced the tire voluntarily a few hundred miles later.

The keys to a good boot

1- fabric comparably as strong as the tire
2- alignment of fabric and tire plies
3- large surface because it depends on the sheer strength of the bonding glue, the boot must also be "stitched" down to a prepped surface to ensure solid bond -- critical.
4- fill or closure of gap in tread rubber if it's open and in the central contact area. Gaps to the side may be left open.

These days people are used to the convenience of a bike shop never too far away (in the USA) or reliable and fast delivery of stuff ordered by phone. But this wasn't always the case. BITD, finding a bike shop equipped to service a derailleur bike on the road meant detours of hundreds of miles. There was no Fedex, and UPS wasn't nationwide, so getting replacements sent meant finding a greyhound depot and waiting for the bus. If touring solo, or with a small group, this meant you had to be self reliant and able to work through surprises making repairs that would last at least a few hundred miles. This is no longer the case in the USA or Europe, but riders touring elsewhere still need to trust their own skills because that's all there is.

At home, I may fix or replace a cut tire depending on the details or my mood, but if I do repair it I feel I can trust my repair which is all that counts.

mapeiboy

I would replace the tire no question ask . Why take the chance with this tire out there where you might have to walk a long distance home . If you buy spare tires in the winter months they are not that expensive . I have at least 4 new tires and 10 inner tubes at home at any time . Your safety come first not the tire .

dsbrantjr

When riding on that tire, use Magic Marker to write your social security number on your arm
so that the police can more easily identify your body ;-)

Wilfred Laurier

Make a boot and adhere it (with cement or some type of tape) to the inside of the tire. Since the Mr Tuffy is not adhesive (afaik) then it will not make a good boot, but might help a proper boot hold pressure better. You can tell if a boot is holding a tire together properly because the tire will not have any major irregularities that you can see or feel while riding. If you can feel a wiggle when the tire rolls past the ground then the boot is not holding pressure as well as the rest of the tire casing. For a 1/4" or 3/8" gash, the mr tuffy might be enough but I would prefer something that sticks the tire back together to prevent debris from migrating in.

Rollfast

And then if the terrain is not flat and optimal, maybe you'll TACO, it not just crash and burn.

Buy more dinged and closeout cans of green beans and such, that will pay for the hurt of the tire replacement over time and become a helpful habit anyway.

Plimogz

This at least seems highly unlikely -- Blunt 35s laced with 36 spokes and anal-retentively tightened to within a quarter division of a TM-1, all around both DS and NDS.
Mind you, combined with 2.35" Big Apples, I expect that one of my wheels probably weights half again as much a some of the light & fancy wheelsets out there.

But I do take your point -- i.e. you do not hold high hopes for my kludged repair holding out in the long run -- fair enough.

Trevtassie

You've got Big Apples, so you're lucky, they are probably one of the few bike tires big enough to take a car tire patch. I don't know if they sell Rema Tiptop in the states (Yep they do!) Go to your local car tire shop and see if they have one of the smallest ones- REMA TIP TOP - REMA TIP TOP Universal tire repair units (UP): UP-3 Universal repair unit UP 3 . They also come in bias and radial flavours, any of them would do provided they are small enough. Tire patches have cords inside them so they will act as a seal and a boot to stop crap from coming through. Use the Special Cement BL or Blue with them.
Oh yeah, before you put the patch on, superglue the cut up, so the patch helps hold it closed.

clydeosaur

A trip to the hospital is not worth the lost $. I know it sucks, I've been there. However, I value my neck alot more than the cost of a tire.

fietsbob

hang it on the wall make a Little Bike momento shrine with in it.

FBinNY 

There are multiple comments expressing a similar notion that a blown tire can somehow lead to injury.

We need to consider this.

Tires blowing or flatting while riding is by no means a rare event. If this were to commonly lead to injury, then we'd be hearing countless reports, and more important, should maybe give up riding altogether until tire technology improves, with some kind of safe run flat feature.

The truth is that whether it's a new tire in perfect condition, or a repaired one, there's always the risk of a blowout, but rarely a risk of it leading to anything worse than inconvenience, and sometimes a dented rim.

So arguments on whether to boot a cut tire or replace it shouldn't hinge on vague threats of injury, but on the practical realities of how well a repaired tire will ride, ie. whether it'll thump with every revolution, and the time and effort to make the repair vs. the life of the repair, and of course on the level of inconvenience involved if the repair fails on the road.